1. Technical Fields
The invention relates to a method and an apparatus for forming and introducing wave windings, with straight portions joined by winding heads, into rotor or stator lamination packets of electrical machines.
2. The Related Art
For a fairly long time, for instance from European Patent Disclosures EP 1 012 951 D1 and EP 0 604 792 A2 as well as U.S. Pat. No. 5,881,778, it has been known to create wave windings, in particular distributed wave windings for producing motor vehicle generators, using a winding nozzle revolving around a template or a template revolving in front of a fixed winding nozzle, and to draw the thus-formed annular wave windings axially into a stator.
In the attempt to attain an optimal filling factor of the stator slots with as little copper as possible and at the same to attain winding heads that are small, well-ventilated and generate only relatively little running noise, stators with many radially inwardly open slots of rectangular cross section have been created in accordance with EP 1 120 881 A2, into which slots wave windings of rectangular coil wire are placed in such a way that in the cross section of a slot the cross sections through the coil wire with a plurality of radial layers form one row extending along the slot and fill up the cross section of the slot. The difficulty in producing a stator of this kind is that the thick rectangular wire, whose width is equivalent to the slot width, can be deformed only with difficulty in a conventional winding and pulling-in process, and normally the winding heads that protrude from the face end beyond the stator lamination packet, because there are so many coil windings that overlap on the circumference and because of the poor deformability of the coil wire, add up to an excessively large radial width, which is practically impossible to reduce using conventional winding head forming tools.